docker-compose pollutes the working directory

[gfiedler]

When docker-compose is used with the example docker-compose.yml to start a local test server, then a folder resources with root permission is created within the source directory:

$ docker-compose up -d
$ ls -ln src
drwxr-xr-x 2 1000 1000  4096 Apr  2  2018 archetypes
-rw-rw-r-- 1 1000 1000  1085 Jan  2 14:21 config.toml
drwxr-xr-x 2 1000 1000  4096 Jan  2 14:13 content
drwxr-xr-x 2 1000 1000  4096 Apr  2  2018 data
-rw-rw-r-- 1 1000 1000   348 Jan  2 14:23 docker-compose.yml
drwxr-xr-x 2 1000 1000  4096 Apr  2  2018 layouts
-rw-r--r-- 1 1000 1000 20132 Apr  2  2018 LICENSE
-rw-r--r-- 1 1000 1000   378 Apr  2  2018 README.md
drwxr-xr-x 3    0    0  4096 Jan  2 14:24 resources
drwxr-xr-x 5 1000 1000  4096 Dez 26 11:16 static
drwxr-xr-x 4 1000 1000  4096 Jan  2 12:56 themes

I expect the source directory not to be modified by the test server.